Table 2 Medical error definitions from the medical literature

James Reason's definition

The failure of planned actions to achieve their desired goal. [55]

Based on James Reason's definition.

Failure of a planned action to be completed as intended or use of a wrong plan to achieve an aim; the accumulation of errors results in accidents. [33]

The failure of a planned action to be completed as intended (i.e., error execution) or the use of a wrong plan to achieve an aim (i.e., error of planning). [58]

The failure of a planned action to be completed as intended or the use of a wrong plan to achieve an aim. Errors can include problems in practice, products, procedures, and systems. [59]

From essays, editorials and reviews

An unintentional deviation from standard operating procedures or practice guidelines. [60]

Deviation in a process of care that may or may not cause harm to patients. [61]

An adverse event or near miss that is preventable with the current state of medical knowledge. [62]

An act of commission or omission that substantively increases the risk of a medical adverse event. [63]

A failure of a structure or process only to the extent that it prevents maximizing the outcomes of interest. [43]

A failure to perform an intended action which was correct given the circumstances. It can only occur if there was or should have been an appropriate intention to act on the basis of a perceived or remembered state of events and if the action finally taken was not that which was or should have been intended. [64]

Errors in healthcare are by definition, human errors, and human errors are errors in human actions. [65]

Underlying causes of failed decisions for the failed delivery of care.... Errors are the causes of the failed processes, whether they are in decision making or in treatment delivery. [38]

Failure to meet reasonable expectations for goal-directed activity. [42]

Mistakes that encompass not only lapses in safety (mistakes in the provision of health care that expose patients to "additive" risk), but also include inattention to extant risks that patients bring to the encounter. [66]

An act in the process of care that could harm a patient, therefore, measures of medical errors can be considered process measures. [19]

Used in research and reporting

An act of commission or omission that caused, or contributed to the cause of, the unintended injury. [49]

Any event you don't wish to have happen again, that might represent a threat to patient safety. [48]

Anything that happened in your own practice that should not have happened, that was not anticipated and that makes you say, "that should not happen in my practice and I don't want it to happen again. [10]

A commission or omission with potentially negative consequences for the patient that would have been judged wrong by skilled and knowledgeable peers at the time it occurred, independent of whether there were any negative consequences [35]

A failure to meet some realistic expectation (an action, process, diagnosis or endpoint). [41]

An unintended event, no matter how seemingly trivial or commonplace, that could have harmed or did harm a patient. [9]

An event that was not completed as intended and/or meant that work was disrupted in some way. [23]

Used in research and surveys with patients and the public

Sometimes when people are ill and receive medical care, mistakes are made that result in serious harm, such as death, disability or additional or prolonged treatment. These are called medical errors. [36]

Some examples of medical mistakes are when a wrong dose of medicine is given, an operation is performed other than what was intended for the patient or results of a medical test are lost or overlooked [39]

Preventable incidents that result in a perceived harm [14]